Pony has a problem.

I have an early MH Pony that has a noise that I hope someone can diagnose and tell me what the remedy is for it.
When the clutch pedal is depressed everything is quiet except the smooth running engine. Let out the clutch and there is a loud whirring noise sounding as if the PTO was running but the PTO is off and the spline is not turning at all. Push the clutch in and it is quiet again.
What would be the cause of this and what parts do I need to repair this?.
PS..There is a brand new clutch kit installed that seems to work with no issues.
Thank you for everyones help with this.